The invention relates generally to strapping tools, and more particularly to strap tensioning tools having improved strap guides and methods therefor.
It is known generally to apply tensioned steel or plastic strap about a load with a power or manually operated hand held strap tensioning tool. Some tools also include means for fastening overlapping strap portions after tensioning, while other tools require a separate fastening tool for this purpose. In plastic strap tensioning tools, for example, it is known to include a vibrating jaw that frictionally fuses, or welds, overlapping strap portions. And in steel strap tensioning tools it is known to include a die assembly for sealess joining of overlapping strap portions. Other steel strap tensioning tools merely tension strap while a separate sealing member is crimped about overlapping strap portions by a seal crimping tool.
Strap tensioning tools operate generally by gripping a strap end portion while an overlapping strap portion disposed about the load is tensioned with a feed wheel. During tensioning, the overlapping strap portions and particularly the tensioned strap portion must be maintained in alignment with the feed wheel. It is known generally to provide a strap guide, usually upstream of the feed wheel, to maintain the strap in alignment therewith during tensioning.
Some known strap guides have an actuator mechanism to release strap engaged thereby after tensioning and sealing, for example by moving a lever connected thereto, so that the tool, usually a foot portion thereof, may be separated from the tensioned strap. Tool operators, however, are not receptive to tools having actuatable strap guides since additional labor is required to disengage the strap from the guide. The actuator mechanism also complicates the tool and increases the cost thereof.
Other known strap guides are relatively simple and do not include an actuator mechanism to release tensioned strap from the strap guide. In prior art FIG. 5 of the present application, for example, an end view of a known tensioning tool strap guide 11 is defined generally by downwardly extending side wall portions 12 and 14 between which overlapping strap portions are disposed during tensioning. As the strap is tensioned, however, it is ultimately pulled downwardly from between the strap guiding wall portions 12 and 14, toward the base plate 16 of the tool, as illustrated in prior art FIG. 6 of the present application. This prior art strap guide has the disadvantage that the strap is withdrawn from between the strap guide before tensioning is complete, whereupon it may become misaligned with the feed wheel during tensioning.
The invention is drawn generally toward advancements in the art of strap tensioning tools, and more particularly toward strap tensioning tools having improved strap guides and methods therefor.
An object of the invention is to provide novel strap tensioning tools having improved strap guides and methods therefor that overcome problems in the art.
Another object of the invention is to provide novel strap tensioning tools having improved strap guides and methods therefor that guide strap until tensioning is complete.
A further object of the invention is to provide novel strap tensioning tools having strap guides and methods therefor that do not require user operated release mechanisms to release strap from the strap guide to withdrawal the tool from between a load and strap tensioned thereabout after tensioning.
A further object of the invention is to provide novel strap tensioning tools having strap guides with a strap guiding member that is pivotal to release strap upon withdrawal of the tool from between a load and strap tensioned thereabout.
A more particular object of the invention is to provide a novel strap guide in a tensioning tool and methods therefor comprising generally a base plate, a wall portion disposed at least partially along and extending above a strap support surface of the base plate, a strap guiding member having a pivot end portion pivotally coupled to the tool along the strap support surface generally opposite the wall portion, a biasing member coupled to the strap guiding member to pivotally bias a guide end portion of the strap guiding member above at least a portion of the strap support surface, whereby strap disposed on the strap support surface of the base plate is guided between the wall portion and the strap guiding member during tensioning and is removable therefrom upon withdrawal of the base plate from between the load and tensioned strap.
These and other objects, aspects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the Invention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps are referenced generally by corresponding numerals and indicators.